Brake equalizing apparatus



Feb. 10; 1925. 1,525,666

D. SMITH BRAKE EQUALIZING APPARATUS 2 Sheets-Sheet 1 Filed May 22, 1923IN VEN TOR.

ATTORNEY.

' 5o throug Patented Feb. 10, 1925.

UNITED STATES PATENT OFFICE".

DAVID SMITH, OF LOS ANGELES, CALIFORNIA, ASSIGNOR T UNION TOOL COMPANY,OF TOBRANGE, CALIFORNIA, A CORPORATION OF CALIFORNIA.

BRAKIEi nouauzme APPARATUS.

Application filed May 22, 1923; Serial No. 640,704.

To all whom it may concern: Be it knownthat I, DAVID SMITH, a citizenofthe United States, residingat Los Angeles, in the county of Los Angelesand State of California, have invented a new and useful Brake-EqualizingApparatus, of which the following is a specification.

This invention relates to a brake e uallzing apparatus and isparticularly. a apted to brake-drums of rotary draw works such as usedin drilling oil wells or similar operations. These brake devices usuallyinclude brakebands which are applied to the flanges of the drum, and itis desirable to provide 6 an e ualizing device so that when the brak--ing orce is applied it will be distributed substantially equally betweenthe brakebands. The general object of the invention .is to provide asimple device of this kind which is self-contained, that is to say, theparts are all connected together so that they can be removed as a wholefrom the derrick; also to provide a device of this kind with simplemeans for holdin the live ends'of the brakebands substantially clear ofthe drum, thereby reducing the amount of wear on the brakebands whenthe. drum is running free; also to provide a compact structure of thischaracter in which the dead ends of the bands aresubstantiallycounterweighted so that only a slight movement of theoperatin lever will be necessary in order to app y the braking forcealthough the bands are held out of actual contact with the flan es ofthe brake-drum.

Furtherv o jects of the invention will appear hereinafter. I

he invention consistsin the novel parts and combination. of parts to bedescribed i0 hereinafter, all of whlch contribute to pro duce anefiici'ent brake equalizing apparatus. A preferred embodiment of theinvention is described in the following specification,

while the broad scope ofthe invention is pointed out in the appendedclaims.

.In the drawing:

Figure 1 is a vertical section taken through the derrick floor at oneedge and v .passinglthrough the shaft of the drum and the rock-shaft ofmy equalizing apparatus, portions of the derrick being broken away. Thisview'may be regarded as a section on the line 1--1 of Figure 2.

Figure 2 is a rear elevation of the equal.-.

works. The rock-sha the bracket or sleeve 8 is provided with a izingapparatus showing portions of the derrick roken away.

Figure 3 is a section taken about at the level of the line 3-3 of Figure1 and showmg the lower parts of the mechanism substantially in plan,while the uprights of the derrick frame are shown in horizontal sec-Figure 4 is a vertical section taken on the line 4-4 of Figure 3.

Figure 5 is a similar section on the line 5+5 of Figure 3. Inpracticingmy invention, I provide a plurality of brakebands to cooperate with thedrum. In the present instance, the drum 1 is provided with twobrake-flanges 2 carrying 'two brakebands 3. These brakebands have theirdead ends disposed substantially under-the drum (seeFigfl) and "areconnected together by an equalizing device 4 which operates todistribute the braking force between tlie two brakebands. Thisequalizing device preferably consists of, an equalizing bar 5 the endsof which are connected by pivotins 6 with shackleplates 7 secured to t eendsof the bands. The equalizing device may be anchored in any smtablemanner, but is preferably connected with the other parts so as to.produce a self-contained construction.

In order to accomplish this, I provide a 1 member 8 in the form of abracket which is attached by a pivot-pin 9- tothe equalizer bar at apoint midway between the two brakebands, and this bracket is mounted asa sleeve on a rock-shaft 10 which is capable. of applying the brakingforce to the brake-.: bands. The ends of this shaft are rotatably?mounted in two bearings 11 having means such as the bolts 12 forsecuring the sameto,

the first and second {posts 13 of the draw;

is supp'orted thereby on the outer side of the derrick. I provide meansfor counterweighting the dead ends 7 of the brakebands', and for thispurpose short arm 14 on the side of the shaft remote from the drum,- andon this arm I mount an adjustable counterweight 15 which may be securedat any point desired by means of removable bolt '16. This counterweightis not ofsufiiciefit weight to maintain the dead ends of the bandpressed a ainst the drum flanges, but is merely use to produce afloating efl'ect in the dead ends; that is to say, the counterweightprevents the loose ends from sagging away ofl from the drum flanges andalso 0 erates to reduce the time in which the ban will act after therockshaft 10 is rotated to apply the brake.

In order to enable the rotation of the rock-shaft to tighten the bandson the drum, I provide two sleeves 17 and 18 which are secured to theshaft by keys 19, and in order to insure that there Wlll be no possiblelongitudinal shifting of these sleeves, I provide each sleeve with aset-screw 20 and checknut 21. The sleeves have short arms 22 whichproject toward the drum, and each sleeve carries a wrist pin 23supported in the arms. In the case of the sleeve 18, I may also supportone end of itswrist-pin 23 in a large arm 24 which operates as a socketfor an operating lever 25 for rocking therock-shaft. Suitable means isprovided for securing the live ends 26 of the brakebands to thewrist-pins 23. For this purpose, each band may be provided with abracket 27 carrying adjustable bolts 28; the lowerend of each bolt isformed with an eye through which the wrist-pin 23 is slipped.

I also provide means for counterweightinq the lever 25 and the live ends26 of the ban This may be simply accomplished by providingan adjustablecounterweight 29 mounted on an arm 30 from the sleeve 17 and securedadjustably thereto in a manner similar to that described in connectionwith the counterweight 15. The brakebands are, of course, provided witha suitable liner or wear-strip 31.

. With this organization of parts, it will be evident that thebrakebands and their connected parts constitute a unitary struc ture;that is to. say, 'there are no attachments made to the derrick frame.This enables the apparatus to be com letely removed when desired inorder to e ect repairs or adjustments and it can be immediately replacedby another apparatus so that the drum can be kept in operation withoutunnecessary delay.

One of the, advantages of this construction also resides in the factthat the shaft 10 is a plain shaft and does not have cranks oreccentrics or. other parts forged upon it. I attain the effect of crankson the shaft by means of the wrist-pins which are mounted in the sleeves17 I and 18- which may be formed of castings which are very inexpensiveto construct.

It is understood that the embodiment of the invention described hereinis only one of the many embodiments this invention\ may take and I donot wish to be limited ;in

' the practice of my invention nor in my claims to the particularembodiment set forth. l 1

It isobvious that springs may be substituted for the counterweights, ifdesired.

That I claim is 1. In a brake equalizing apparatus, the combination of adrum, a plurality of brakebands carried 'by the drum, a rock-shafthaving means for rocking the same, means connecting the live ends of thebrakebands to the rock-shaft to actuate the bands to tighten them on thedrum simultaneously, an equalizer bar connected with the dead ends ofthe brakebands, and a member loosely mounted on the rock-shaft,connectedwith the equalizer bar and operating as an anchorage for the dead endsof thc brakebands whereby the braking force is distributed between thedifl'erent brakebands.

2. In a brake equalizing apparatus, the combination of a drum, aplurality of brakebands carried by the drum, a rock-shaft having meansfor rocking the same, means connecting the live ends of the brakebandsto the rock-shaft to' actuate the bands to tighten them on the drumsimultaneously, an equalizer bar connected with the dead ends of thebrakebands, and a member loosely mounted on the rockshaft, connectedwith the equalizer bar and operating as an anchorage for the dead endsof the brakebands whereby the braking force is distributed between thedifferent brakebands, and a counterweight carried by the -ro'ckshaft onthe side thereof remote from the drum-and exerting its force tocounterbalance the weight of the dead ends of the bands.

3. In a brakeequaliz'ing apparatus, the combination of a drum, a pairofbrakebands carried by the drum, a rock-shaft and operating lever forrocking the same, a sleeve on the rock-shaft corres onding to eachbrakeband and connecte with the live ends of the brakebands, an'equalizer bar connecting the dead ends of the brakebands, and a sleeveloosely mounted on the rock-shaft between the brakebands and connectedwith the eqiualizer bar midway be-v tween the two ban s.-

4. In a brake equalizingapparatus, the combination of a drum, a pair ofbrakebands carried by the drum, a rock-shaft and operating leverforrocking the same, a sleeve carrying the said lever rigid on therock-shaft, and corresponding to one -of the brakebands, another sleeverigid on 'the equalizer bar at a point midway between the bands, 2."counterweight carried by'the last named sleeve for substantiallycounterbalancing the equalizer bar and dead endsof the brakebands, and acounterweight carried by the rock-shaft andexerting its force to holdthe live ends of the brakebands out of contact with the drum.

5. A self-contained brakeband equalizing I apparatus, comprising thecombination of device connected with the other ends of the bands andanchored on the rock-shaft.

f 6. In a brakeband equalizing apparatus, the combination of a drum,apair of brakebands carried by the drum, a rock-shaft with an operatinglever for rocking the same, wrist-pins carried by the shaft on the sidetoward the drum, means connecting the wrist-pins with the live ends oftheir corresponding brakebands, a counterweight carried by the shaft onthe sideremote from the drum and operating to hold the live ends of thebrakebands out of contact with the drum, and an equalizing device foranchoring the dead ends of the bands,

7. In a draw works, the combination of a hoisting drum provided with abrake having two brake bands, means secured to ends of the bandstoadjustably pull and tighten the latter, and an equalizing anchorsecured to a stationery support and to the other ends of said bands.

8. In a draw works, the combination of a hoisting drum, two brake drumssecured to rotate with said hoisting drum, brake bands embracing saiddrums, means secured tothe ends of said brake bands to adjustably pulland tighten the latter, a cross-bar ivotally secured to said brakebands, and an anchor pivotally secured to said cross-bar between theends thereof and to a stationa support.

Signed at orrance, California, this 12th day of May, 1923.

DAVID SMITH.

